Our 10 Kw Kubota has 2 blowers. One is pretty good-sized. IIRC, approx 8 -10 amp 120v. and runs off generator. Air is exhausted out the bottom. Secondary smaller blower as well. Maybe 1/2 that size. Lots of air flow. If bus wasn't so heavy I'd have a hover craft. Generator is totally enclosed. No shutdowns due to overheating except for unrelated and/or self-induced problems.

Saw this same situation occur this spring. Kubota engine, Powertech Generator. Owner changed thermostat and was ready to pull radiator and fan. We compared the '95 design to a '98 design. Some are very hard to bleed. In his case, analysis indicated a bad radiator cap. It could not be that simple! Could it? Yes, bad cap.

On my Powertech 10kw with 4 cylinder Kubota, the generator is mounted next to the driver's seat like a front engine facing backwards (alternator facing forward). It was installed through the front door and is serviced from inside from the top-which actually I really like. With the 1" lead insulation, it is pretty quiet inside.For cooling, the radiator is remote mounted under the driver's seat with a single inlet squirrel cage blower sucking the air through the radiator and pushing the hot air out the side of the bus. It uses a 1/2hp totally enclosed fan cooled 2spd motor with belt drive. Use high during the day and low at night for almost silent operation. The gen cabinet is cooled with a 8" inline bathroom ventilator (250cfm) that branches into 2-6" ducts. Then have 2-6" ducts out the back of the cabinet to exhaust the air. The ventilating air blows right on the alternator head. I've been in as high as 108 degree weather with 3 A/C's running, and have not had any cooling problems. Good Luck, TomC

My old Kubota that came on the bus had just those two slots in the compartment, front and back, also? It also had a screened opening in the vertical door but this didn't go to anything outside so I couldn't see how that helped. Never did see how that was enough cooling. The PO remoted the radiator which surely helped but it failed so soon after I used it in hot weather I never had a chance to check it out.

How do you circulate water through a marine exh manifold? It goes overboard on a boat? Mine is dry on the cooling side and the heat exchanger was removed.

I have an 1994 PowerTech/Isuzu 3 cyl diesel 8KW (gen head tag says 7KW?), and a Onan/Kubota 3 cyl diesel 6.5 KW. The Onan/Kubota gen head is physically larger than the powertech gen head by like two or three times.

The Onan was specifically setup and sold as an RV generator, the Powertech is not. The Powertech is just a genny on a frame. Seeing as the 905 Kubota engine runs generators as large as 8 KW, my thinking is the head is much greater capacity than 8KW, and Onan derated it to 6.5 KW for RV use vis a vis possible heat buildup, not knowing exactly how all the idiot RV builders would install it.

Anyway, im going to pull the Kubota out of the Bounder for home standby power and keep the Powertech for the Bus as the Powertech is smaller and lighter. My understanding is keep the Gen head under 40C??